New Monoclonal Antibodies That Define Multiple Epitopes and a Human‐Specific Marker on the Interleukin 2 Receptor Molecules of Primates

Abstract

Twelve hybridoma cell lines producing monoclonal antibodies to the human interleukin 2 (IL-2) receptor (IL-2R) molecule were prepared. These antibodies were characterized by competitive antibody-binding assay and sequential immunoprecipitation assay with four known monoclonal antibodies to the human IL-2R molecule. The twelve new monoclonal antibodies were divided among the four known antibody types, the HIEI-, H-A26-, H-31-, and anti-Tac-type, and an additional new type, the H-48-type. The H-48 antibody did not compete with any other antibodies in the competitive binding assay. The binding of 1-25I-IL-2 to MT-2 cells and the IL-2-dependent growth of normal activated T-cells were both strongly inhibited by all the H-31-and anti-Tac-type antibodies, and partially or slightly inhibited by HIEI-and H-A26-type antibodies, but were not inhibited by the H-48 antibody. Thus, the same type of monoclonal antibodies had a similar effect on the function of IL-2R. These results suggest that epitopes for the same type of antibodies could be single identical epitopes or epitopes closely associated with each other. On the other hand, these antibodies also reacted variously with a panel of various human and simian lymphoid cell lines immortalized with human T-cell leukemia virus type-I (HTLV-I) : the H-45 antibody reacted only with the human cell lines, the H-Cl and H-44 and H-47 antibodies reacted with human and ape cell lines, and the other antibodies reacted with cell lines of humans, apes and Old and New World monkeys. These differences in the reactivity of the antibodies with the primate cell lines suggest that the antigenic structure of the IL-2R molecule changed during evolutionary divergence of the primates.

Natural OX40L expressed on human T cell leukemia virus type-I-immortalized T cell lines interferes with infection of activated peripheral blood mononuclear cells by CCR5-utilizing human immunodeficiency virus

“…Neutralizing mAbs against human RANTES, MIP-1α, and MIP-1β were purchased from R&D systems (Minneapolis, MN). The mouse mAbs produced in our laboratory included anti-OX40L (blocking clone 5A8 [34] and clone HD1, unpublished), anti-human OX40 (non-blocking clone B-7B5 and clone 17D8 [35]), anti-HIV-1 p24 (clones NP-24 and 2C2 [21]) and anti-CD25 (clone H-8) [36]. The rat mAbs included anti-human OX40 (blocking clone W4-54) and anti-HCV (clone Mo-8) [25,37]).…”

Monoclonal antibody defining Tax1 protein of human T-cell leukemia virus type-I.

“…The spleen cells were fused with P3/X63-Ag8U1 (P3U1) murine myeloma cells by the method described previously (Tanaka et al 1986a). The isotype of MAbs was determined by the agar gel double diffusion method using rabbit antisera against murine immunoglobulin classes and subclasses (Cappel, PA, USA).…”

“…Immunological characterizations of px-gene products have not been performed yet because of a lack of monoclonal antibodies (MAbs) to various epitopes of the products, although one MAb against C-terminal region of the taxi protein synthesized in Escherichia coli has been reported (Watanabe et al 1986). We have prepared murine MAbs against various components of HTLV-I virions and HTLV-I-infected cells (Tanaka et al 1985(Tanaka et al , 1986a. In a series of the studies, we have established a MAb against native products of the taxi-gene.…”

Overexpression in Escherichia coli of a methionine‐free designed interleukin‐2 receptor (Tac protein) based on a chemically cleavable fusion protein

“…All reagents for protein microsequence analysis were purchased from Applied Biosystems. IgGl -type monoclonal antibodies (mAb) H-48 and H-31 [25] were kindly provided by K. Sugamura (Tohoku Kyoto University, Sendai, Japan) and mAb against p-galactosidase were kindly provided by M. Fitzek (GBF Braunschweig, FRG). A rabbit was immunized with purified polypeptide pl74-191 conjugated keyhole limpet hemocyanin comprising residues 174 -191 of the human IL-2Ra according to Kuo and Robb [26].…”